package com.smart.carey.util;


import javax.crypto.*;
import javax.crypto.spec.SecretKeySpec;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
public class AESUtil {
      private static final String KEY_ALGORITHM = "AES";
    private static final String DEFAULT_CIPHER_ALGORITHM = "AES/ECB/PKCS5Padding";//默认的加密算法


    /**
     * AES 加密操作
     *
     * @param content 待加密内容
     * @param password 加密密码
     * @return 返回Base64转码后的加密数据
     */
    public static String encrypt(String content, String password) {
        try {
            Cipher cipher = Cipher.getInstance(DEFAULT_CIPHER_ALGORITHM);// 创建密码器
            byte[] byteContent = content.getBytes("utf-8");
            cipher.init(Cipher.ENCRYPT_MODE, getSecretKey(password));// 初始化为加密模式的密码器
            byte[] result = cipher.doFinal(byteContent);// 加密
            String encryptResultStr = parseByte2HexStr(result);
            return encryptResultStr;
        } catch (Exception ex) {
            ex.printStackTrace();
         }

        return null;
    }


    /**
     * AES 解密操作
     *
     * @param content
     * @param password
     * @return
     */
    public static String  decrypt(String content, String password) {

        try {
            //实例化
            Cipher cipher = Cipher.getInstance(DEFAULT_CIPHER_ALGORITHM);
            byte[] result= parseHexStr2Byte(content);
            //使用密钥初始化，设置为解密模式
            cipher.init(Cipher.DECRYPT_MODE, getSecretKey(password));
            //执行操作
            result = cipher.doFinal(result);
            return new String(result);
         } catch (Exception ex) {
            ex.printStackTrace();
         }

        return null;
    }



    /**
     * 生成加密秘钥
     *
     * @return
     */
    private static SecretKeySpec getSecretKey(final String password) {
        //返回生成指定算法密钥生成器的 KeyGenerator 对象
        KeyGenerator kg = null;

        try {
            kg = KeyGenerator.getInstance(KEY_ALGORITHM);

            SecureRandom random = SecureRandom.getInstance("SHA1PRNG");
            random.setSeed(password.getBytes());

            //AES 要求密钥长度为 128
            kg.init(128, random);

            //生成一个密钥
            SecretKey secretKey = kg.generateKey();

            return new SecretKeySpec(secretKey.getEncoded(), KEY_ALGORITHM);// 转换为AES专用密钥
        } catch (NoSuchAlgorithmException ex) {
            ex.printStackTrace();
         }

        return null;
    }



    /**
     * 将二进制转换成16进制
     * @method parseByte2HexStr
     * @param buf
     * @return
     * @throws
     * @since v1.0
     */
    public static String parseByte2HexStr(byte buf[]){
        StringBuffer sb = new StringBuffer();
        for(int i = 0; i < buf.length; i++){
            String hex = Integer.toHexString(buf[i] & 0xFF);
            if (hex.length() == 1) {
                hex = '0' + hex;
            }
            sb.append(hex.toUpperCase());
        }
        return sb.toString();
    }

    /**
     * 将16进制转换为二进制
     * @method parseHexStr2Byte
     * @param hexStr
     * @return
     * @throws
     * @since v1.0
     */
    public static byte[] parseHexStr2Byte(String hexStr){
        if(hexStr.length() < 1)
            return null;
        byte[] result = new byte[hexStr.length()/2];
        for (int i = 0;i< hexStr.length()/2; i++) {
            int high = Integer.parseInt(hexStr.substring(i*2, i*2+1), 16);
            int low = Integer.parseInt(hexStr.substring(i*2+1, i*2+2), 16);
            result[i] = (byte) (high * 16 + low);
        }
        return result;
    }



    public static  void main(String[] args){
        try {
                String AESText =encrypt("64ff818f9ca88f91f6c4a50839322dfd&&1530082205385","KEY");
                System.out.println(AESText);
                String decryptFrom  = decrypt(AESText,"KEY");
            System.out.println("解密后：" + new String(decryptFrom));

        } catch (Exception e) {
            e.printStackTrace();
        }
    }

}
